1. Field of the Invention
This invention relates to a cassette housing shelf that is adapted for accommodating various sized cassettes in cassette auto-changers used for continuous, long-time video recording or reproducing, for example, in a television broadcasting station.
2. Description of the Related Art
The applicant of this invention disclosed a various-sized-cassette housing shelf for video-cassette auto-changers in Japanese Patent Application No. 63-84591.
In this cassette housing shelf, when a large-sized cassette is inserted into a cassette housing portion formed thereupon, both sides of the cassette are guided by a pair of inside walls, respectively, and when a small-sized cassette is inserted into the cassette housing portion, both sides of the cassette are guided by a pair of guiding walls that are provided on the respective inner sides of the pair of inside walls.
Thus, center lines of both the large-sized cassette and the small-sized cassette coincide with that of the cassette housing portion.
The pair of guiding walls for the small-sized cassette are movable between the inside and the outside of the cassette housing portion, and when the large-sized cassette is inserted, a pair of detectors provided on both sides of a cassette inlet, detect the cassette, and thus, the pair of guiding walls are moved to the outside of the cassette housing portion by drive means, which is driven in response to control signals from the detectors.
However, in such prior shelf in which the center lines of the two kinds of cassettes coincide with that of the cassette housing portion, it is not easy to insert the small-sized cassette into the cassette housing portion through a cassette inlet, because the small-sized cassette must be inserted through the relatively larger cassette inlet, which has been formed to enable the large-sized cassette to pass therethrough, and then interposed between the pair of guiding walls which are spaced apart by a distance smaller than the width of the cassette inlet.